Description:Publication and maps of the Evitts Creek and Pattersons Creek quadrangles at a 1 to 24000.The Evitts Creek and Pattersons Creek quadrangles occupy about 115 square miles of mountainous western Maryland and contiguous parts of Pennsylvania and West Virginia. The exposed strata consist of about 8,000 feet of sedimentary rocks ranging in age from Late Ordovician to Late Devonian. The stratigraphic sequence is divided into 21 formations, several of which are subdivided into members. In ascending order the stratigraphic units are: the Juniata Formation of Ordovician age; Tuscarora Quartzite, Rose Hill Formation, Reefer Sandstone, Rochester Shale, McKenzie Formation, Bloomsburg Red Beds, Wills Creek Shale, and Tonoloway Limestone of Silurian age; Keyser Limestone of Silurian and Devonian (?) age; the Helderberg Group (Coeymans Limestone, New Scotland Limestone, and Mandata Formation), Oriskany Group (Shriver Chert and Ridgeley Sandstone), Needmore Shale, Marcellus Shale, Mahantango Formation, Harrell Shale (including the Burket Black Shale Member in the basal part), Woodmont Shale, and Chemung(?) Formation of Devonian age. The hard and resistant formations such as the Juniata Formation, Tuscarora Quartzite, and Ridgeley Sandstone commonly form the large hills and mountains in this region. The soft and easily eroded formations such as the Wills Creek Shale, Needmore Shale, Marcellus Shale, and Harrell Shale generally underlie lowlands and valleys.
Publication Date: Jan 01, 1964